The field of the invention pertains to the field of temporarily covering or enclosing objects and structures of large size during treatment or processing and, in particular, to enclosing such objects in a manner that contains and retains materials that otherwise would be released to the environment. Only recently a significant demand for means to cover large objects and structures has arisen because of new rules to prevent the release of old paint, sand blasting materials, new paint overspray and asbestos to the environment.
Means to quickly cover or uncover a large object have been available for many years in a variety of forms such as that disclosed in U.S. Pat. No. 1,759,628 wherein an automobile may be quickly covered and uncovered. More recently U.S. Pat. No. 4,787,173 discloses a means to quickly cover and uncover fruit trees with minimal damage to the trees.
U.S. Pat. No. 4,794,974 discloses a dust curtain for interior protection from dust generated in a portion of an interior room. U.S. Pat. 3,945,106 discloses a means of constructing a natural draft cooling tower by raising a ring on a central tube, the ring having a cable assembly suspended therefrom. The cable assembly supports a larger ring to provide a fixed upper diameter for the tower. The cable configuration provides the proper geometric shape for the cooling tower and a support upon which are attached panels of plastic, metal or asbestos cloth.
The above approaches to enshrouding an object or structure do not suggest means to enshroud structure as large as municipal water towers and petroleum storage tanks. Under new rules being mandated for environmental protection, enshrouding is being required for the sand blasting and painting of such large structures to prevent contamination of the environment with dust, paint chips and paint spray.